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Flower

When to plant Calendula

Computed from land-grant Extension planting-window rules (cited below), localized to real ZIP-level median frost dates, not a single national guess. These are national-generic rules by hardiness class; individual state Extension offices layer their own regional adjustment on top (earlier in the Deep South, later in the Upper Midwest). Enter your ZIP for your own dates, or read the four representative locations below.

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Representative timing, by climate band

When to plant Calendula in four US climates

Each column is the most nursery-dense location in our directory within that USDA zone band, computed from that location's own real median frost dates, not a made-up example.

Zones 10-13 (hot, frost rare or absent) (Loxahatchee, FL): Frost is rare here (about 359 frost-free days a year); most years see little or no hard freeze. This is a hardy crop. In climates like this one, hardy and semi-hardy crops typically go in during the cooler months (fall through late winter), not on a frost-relative schedule.

Calendula is a hardy annual. University of Illinois Extension groups it with pansy, snapdragon, sweet alyssum, and dusty miller as a hardy example, planted about four weeks before the frost-free date, and Clemson Cooperative Extension's Growing Annuals factsheet agrees. NC State Extension's Plant Toolbox gives the numbers this page runs on: start seed indoors six to eight weeks before your last frost, and direct-sow just before that date.

NC State also says seedlings go out "just after the last frost date," but without a specific week count attached, so that field renders blank here rather than a guessed number; the direct-sow window already covers the practical planting range.

Clemson mentions a fall-sowing option for calendula but gives no specific weeks-before-first-frost figure, so that field is blank too, and no extension source gave a sourced first-bloom day count. At the nursery, calendula is sold as seed for the most part, though started plugs also show up.

Sourcing notes

Hardy annual: Clemson Growing Annuals and University of Illinois Extension's Annuals page both list calendula as hardy (Illinois groups it with pansy, snapdragon, sweet alyssum, dusty miller, ~4 weeks before frost-free date). NC State Extension Plant Toolbox gives the numeric detail used here: indoor sow 6-8 weeks before last frost, direct-sow "just before the last frost date," transplant/seedlings set out "just after the last frost date." Clemson notes a fall-sowing option ("seed in the fall") but gives no specific week-before-first-frost count, so fall_planting_weeks_before_first_frost is left blank rather than estimated. No extension source gave a sourced first-bloom day count (non-extension gardening sites cited 6-8 weeks but were excluded per the no-fabrication/extension-sourcing rule).

Sources

• Clemson Cooperative Extension Home & Garden Information Center, Growing Annuals (HGIC 1152) (accessed 2026-08-04)
• University of Illinois Extension, Annuals (Flowers) (accessed 2026-08-04)
• NC State Extension Gardener Plant Toolbox, Calendula officinalis (accessed 2026-08-04)